If GPE is the VXLAN evolution, why it request a new UDP port? If GPE is a new protocol, why it has to align with VXLAN format?
Lucy -----Original Message----- From: nvo3 [mailto:[email protected]] On Behalf Of Fabio Maino Sent: Wednesday, July 16, 2014 5:47 PM To: Dino Farinacci Cc: [email protected] Subject: Re: [nvo3] Comments on http://tools.ietf.org/html/draft-quinn-vxlan-gpe-03 Dino, GPE is not changing VXLAN nor LISP, as today's implementations cannot be changed. GPE is proposing a converged extension of both protocols that add some new features that, I believe, are needed. All of VXLAN features are supported in GPE. In the case of LISP, unfortunately, two features (nonce and map-versioning) could not be accommodated in GPE. This is not very different than any of today's LISP implementations that may decide to not support those two features (for whatever reason: cost, complexity, use cases addressed by the implementation... independently from GPE). What GPE is trying to do is to simplify next generation implementations by keeping GPE as close as possible to the existing encapsulations, adding on top of those. I maintain that an implementation supporting GPE, LISP and VXLAN will be more cost effective than one that supports VXLAN, LISP and a clean slate protocol, and may have better chances of being deployed. Fabio On 7/16/14, 1:05 PM, Dino Farinacci wrote: > Well, if you want to really care about customers, creating all these > variations is not doing justice to them. If you want less combinations, you > keep VXLAN the way it is right now, with no changes. You keep LISP the way it > is right now with no changes. You get L2 and L3 overlays with a unified pull > control-plane in draft-maino-nv03-lisp-cp (preaching to the author ;-) or use > BGP as an alternative push control-plane. > > As for NSH, you create a new header because it is completely new requirement > and has not be deployed anywhere. Since it is brand new, you need new > hardware and code to be developed to support it. So changing VXLAN and LISP > to support NSH doesn't make sense because you inject change in 3 places > rather than in 1 new place, creating more protocol machinery, complexity, and > combinations that will frustrate customers (not to mention vendor call > centers). > > Less entropy please, > Dino > > On Jul 15, 2014, at 10:51 PM, Fabio Maino <[email protected]> wrote: > >> Dino, >> I believe that using a format that can share as much as possible with the >> two protocols deployed today will give a better chance to GPE to be >> implemented, as vendors may want a cost effective way to migrate to the new >> protocol while preserving compatibility with legacy implementations. >> >> The fact that GPE provides a way to be extended, either with a shim a-la NSH >> or making availabe more bits in the header for future features, I think >> opens up to the addition of new features (explicit service tagging, as an >> example) in a more organic way than trying to use the few bits left in VXLAN >> or LISP. >> >> Unfortunately, in the LISP case, this comes to the expense of some features >> that are in the current specification, but I believe those same features can >> be mapped on a GPE+shim header, so a new implementation would be able to >> provide the equivalent of those features (e.g. nonce). >> >> It's hard to find the right balance between backward compatibility and >> evolution of the encapsulation, but I believe GPE gets to a decent >> compromise. >> >> Thanks, >> Fabio >> >> >> >> On 7/15/14, 4:47 PM, Dino Farinacci wrote: >>>>> Hi VXLAN-gpe authors, >>>>> >>>>> Abstract: technically this is not extending a VXLAN but defines a >>>>> new protocol that looks similar to VXLAN (demonstrated by need for >>>>> new UDP port assignment). >>>> We are trying to balance re-use of the VXLAN format and the need to >>>> support existing non-GPE hardware that might already be deployed. We >>>> looked at using the same port, and the new one, and decided, at this point >>>> that a new port is easier for migration but since the packet format is >>>> essentially VXLAN to keep the VXLAN name. >>> Paul, this design seems to be going in circles. If a new port is used, why >>> not make the new port for VXLAN mean layer-3 protocols follow? Or better >>> yet, have a demux field after the VXLAN header so you don't have to use >>> VXLAN header bits. Because the P-bit is using a precious bit in the >>> VXLAN/LISP header and the nonce field that can be used for other things (we >>> have history that shows a nonce in the header is a cheap form of obscure >>> security). >>> >>> If you do this then you have no compatibility problems with initial VXLAN >>> and LISP implementations. >>> >>> And, most importantly, there will be less confusion in the marketplace. >>> >>> Dino >>> _______________________________________________ >>> nvo3 mailing list >>> [email protected] >>> https://www.ietf.org/mailman/listinfo/nvo3 >> _______________________________________________ >> nvo3 mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/nvo3 _______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3 _______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3
